Mushrooms Upon Mushrooms

Say ‘‘mushroom mille-feuille’’ to most veteran cooks and eaters, and they will most likely picture a golden mound of puff pastry filled with wild mushrooms in cream and herbs — a fine dish, if old-fashioned and increasingly rare.

This is nothing like that.

Early this summer, I was steered by the elbow to Dirty French, the newest New York restaurant from Rich Torrisi and his partners. Their first, Torrisi Italian Specialties, a reimagining of Italian-American classics, opened in 2009 on Mulberry Street. Dirty French, which opened in the fall of 2014 on Ludlow Street, handles sort-of-classic French food in a similarly playful manner.

And that’s where I was commanded by my dinner companion to order the mushroom mille-feuille: ‘‘It’s the best thing on the menu,’’ he insisted. I wasn’t sure what would be placed before us, but I certainly wasn’t expecting this: layers of paper-thin mushroom slices, seasoned, buttered, pressed in a pan and chilled for a day, then sliced and seared and served with a piquant sauce.

Think of the best pommes Anna, but with the firm, chewy texture of good mushrooms, perfectly crisped and graced with a colorful purée. It’s not literally a mille-feuille, which translates as ‘‘a thousand leaves,’’ but more like 50 or 75 layers. The sauce, which on my first visit was a green curry made with ramps, is neither irrelevant nor lily-gilding, though the mille-feuille itself is so enticing that just a little soy sauce and lemon would complement the mushrooms’ earthiness well.

Simple as it sounds, this dish was the most interesting thing I’d eaten in months. The next morning, I was on the phone with Torrisi, asking him if the mille-feuille was too complicated for us — that is, for you and me, ordinary home cooks. ‘‘With a little patience, anyone can do it,’’ he said. Soon I was in the Dirty French kitchen, where Torrisi, along with Dai Matsuda, the chef de cuisine, greeted me with a huge pile of sliced king trumpet mushrooms and a pot of melted butter. In their hot and busy kitchen, we went to work, buttering, salting, layering and repeating.

King trumpet mushrooms, also called king oysters, aren’t the most flavorful mushrooms, but their meaty texture is unparalleled. You start by slicing them thinly. Although the restaurant uses a slicing machine, a mandoline works well. You layer these slices in a loaf pan, a terrine or something similar. Each layer is brushed with that melted butter and sprinkled with salt; the thing is piled high, way above the pan’s rim. You roast it, weigh it down heavily and then refrigerate it. The result is a firm mushroom loaf that you can slice like a bread, revealing the many layers. Then you sear these slices in olive oil until crisp. There’s something about critical mass here — I tried making the loaf in a smaller pan, with a smaller pile of mushrooms, and it just wouldn’t hold together. Make the full loaf. Even if there were only two people eating these irresistible slices, you would finish the loaf off long before you ever grew tired of it.

I asked Torrisi how the dish came about. At the original restaurant, he said, they got in the habit of ‘‘skewering a few items very simply and grilling them over charcoal and wood. One of those things was a potato mille-feuille.’’ He said he and his team became ‘‘totally obsessed’’ with ‘‘mille-feuilling everything.’’ They tried 20 or 25 different vegetables before turning to long, stout king trumpet mushrooms. ‘‘And the second I tasted these, I was like, ‘Holy [expletive].’ Everyone loved it.’’

Before Dirty French opened, Torrisi knew the mushroom mille-feuille was the kind of dish he wanted to serve there: sort of French, but ‘‘cool and memorable’’ as well. The green curry I tried on my first visit was mind-blowing on its own but also five times more complicated to make than what it was meant to grace. Torrisi suggested we try a yellow tomato coulis in its place. It’s the perfect match: the earthy but not overpoweringly flavored mushrooms, crisp, chewy and buttery, surrounded by a whirlwind of acidity and color.

And all of this can be yours at home. All you need is a pile of mushrooms, a few sticks of butter, a mound of tomatoes and herbs and some time. You may end up like me: obsessed, making the dish for anyone I can and finishing off the last seared slices myself.